1. O. Roelen discovered which famous reaction?

Hydroformylation

2. What is the first binary metal−carbonyl complex?

Ni(CO)₄

3. Who discovered the hydroboration reaction?

H. C. Brown

4. Reductive elimination reaction is favored by what kind of ligands? 

Sterically demanding

5. β−halide elimination is mainly observed for what type of metal halide complexes?

Metal fluorides